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From: wmb@firmworks•com (Mitch Bradley)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v2 01/12] ARM: Orion: DT support for IRQ and GPIO Controllers
Date: Thu, 05 Jul 2012 08:36:53 -1000	[thread overview]
Message-ID: <4FF5DEC5.9030707@firmworks.com> (raw)
In-Reply-To: <201207051454.24475.arnd@arndb.de>

On 7/5/2012 4:54 AM, Arnd Bergmann wrote:
> On Thursday 05 July 2012, Sebastian Hesselbarth wrote:
>> Andrew,
>>
>> is it possible to group all gpio banks into one DT description?
>> For mach-dove it could be something like:
>>
>> gpio: gpio-controller {
>>          compatible = "marvell, orion-gpio";
>>          ...
>>
>>          bank0 at d0400 {
>>                  reg = <0xd0400 0x40>;
>>                  ngpio = <8>;
>>                  mask-offset = <0>;
>>                  interrupts = <12>;
>>          };
>>
>>          bank1 at d0400 {
>>                  reg = <0xd0400 0x40>;
>>                  ngpio = <8>;
>>                  mask-offset = <8>;
>>                  interrupts = <13>;
>>          };
>
> This way you have multiple nodes with the same register
> and different names, which is not how it normally works.

The "mask-offset" property is really a "reg" in disguise.

"reg" is considerably more general than just "memory mapped
register address".  It really means "any numeric identifier
that makes sense in the context of a parent device".

Therefore, one could say:

gpio: gpio-controller {
          compatible = "marvell, orion-gpio";
          reg = <0xd0400 0x40>;
          #address-cells = <1>;
          #size-cells = <0>;
          ...

          bank0 at 0 {
                  reg = <0x0>;
                  ngpio = <8>;
                  mask-offset = <0>;
                  interrupts = <12>;
          };

          bank1 at 8 {
                  reg = <0x8>;
                  ngpio = <8>;
                  interrupts = <13>;
           };

>
>>
>> This would have the advantage that DT describes gpio-to-irq dependencies.
>> Moreover, nodes that reference gpios can do gpios = <&gpio 71 0>; instead of
>> gpios = <&gpio3 7 0>;
>
> Is that desired?
>
> The device tree representation should match what is in the data sheet
> normally. If they are in a single continuous number range, then we should
> probably have a single device node with multiple register ranges
> rather than one device node for each 32-bit register. Looking at
> arch/arm/plat-orion/gpio.c I think that is not actually the case though
> and having separate banks is more logical.
>
> Something completely different I just noticed in the original patch:
>
>> @@ -90,6 +74,27 @@ static void pmu_irq_handler(unsigned int irq, struct irq_desc *desc)
>>        }
>>   }
>>
>> +static int __initdata gpio0_irqs[4] = {
>> +     IRQ_DOVE_GPIO_0_7,
>> +     IRQ_DOVE_GPIO_8_15,
>> +     IRQ_DOVE_GPIO_16_23,
>> +     IRQ_DOVE_GPIO_24_31,
>> +};
>> +
>> +static int __initdata gpio1_irqs[4] = {
>> +     IRQ_DOVE_HIGH_GPIO,
>> +     0,
>> +     0,
>> +     0,
>> +};
>
> I think the latter one needs to be
>
> +static int __initdata gpio1_irqs[4] = {
> +     IRQ_DOVE_HIGH_GPIO,
> +     IRQ_DOVE_HIGH_GPIO,
> +     IRQ_DOVE_HIGH_GPIO,
> +     IRQ_DOVE_HIGH_GPIO,
> +};
>
> so we register all four parts to the same primary IRQ. The
> same is true for the devicetree representation.
>
> 	Arnd
>
> _______________________________________________
> devicetree-discuss mailing list
> devicetree-discuss at lists.ozlabs.org
> https://lists.ozlabs.org/listinfo/devicetree-discuss
>

  parent reply	other threads:[~2012-07-05 18:36 UTC|newest]

Thread overview: 64+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-07-03 14:22 [PATCH v2 00/12] IRQ, GPIO SPI, I2C, etc DTC support Andrew Lunn
2012-07-03 14:22 ` [PATCH v2 01/12] ARM: Orion: DT support for IRQ and GPIO Controllers Andrew Lunn
2012-07-05  8:15   ` Andrew Lunn
2012-07-05  9:02   ` Thomas Petazzoni
2012-07-05  9:48     ` Andrew Lunn
2012-07-05 10:10       ` Thomas Petazzoni
2012-07-05 10:25         ` Andrew Lunn
2012-07-05 10:11       ` Arnaud Patard (Rtp)
2012-07-05 10:20         ` Thomas Petazzoni
2012-07-05 10:38           ` Arnaud Patard (Rtp)
2012-07-05 11:42             ` Thomas Petazzoni
2012-07-05 11:48               ` Andrew Lunn
2012-07-05 12:09                 ` Sebastian Hesselbarth
2012-07-05 12:58       ` Thomas Petazzoni
2012-07-05 13:15         ` Andrew Lunn
2012-07-05 13:28           ` Thomas Petazzoni
2012-07-05 13:33             ` Andrew Lunn
2012-07-05 13:36               ` Thomas Petazzoni
2012-07-05 12:25   ` Arnd Bergmann
2012-07-05 13:08     ` Andrew Lunn
2012-07-05 13:47       ` Arnd Bergmann
2012-07-05 13:54         ` Andrew Lunn
2012-07-05 15:47           ` Arnd Bergmann
2012-07-05 14:14       ` Sebastian Hesselbarth
2012-07-05 14:43         ` Andrew Lunn
2012-07-05 14:54         ` Arnd Bergmann
2012-07-05 15:51           ` Sebastian Hesselbarth
2012-07-05 16:30             ` Arnaud Patard (Rtp)
2012-07-05 16:16           ` Andrew Lunn
2012-07-06 20:08             ` Arnd Bergmann
2012-07-06 21:00               ` Andrew Lunn
2012-07-07  0:24                 ` Where to put a large bootloader-supplied device tree on ARM ? Mitch Bradley
2012-07-07  1:23                   ` David VomLehn (dvomlehn)
2012-07-07  1:59                     ` Mitch Bradley
2012-07-09  4:30                       ` Nicolas Pitre
2012-07-12  6:52                         ` Mitch Bradley
2012-07-12 18:16                           ` Nicolas Pitre
2012-07-12 20:34                           ` Rob Herring
2012-07-12 21:38                             ` [U-Boot] " Albert ARIBAUD
2012-07-12 21:47                               ` Wolfgang Denk
2012-07-13  1:28                                 ` Rob Herring
2012-07-13  6:45                                   ` Albert ARIBAUD
2012-07-05 18:36           ` Mitch Bradley [this message]
2012-07-03 14:22 ` [PATCH v2 02/12] SPI: Refactor spi-orion to use SPI framework queue Andrew Lunn
2012-07-03 14:22 ` [PATCH v2 03/12] spi-orion: remove uneeded spi_info Andrew Lunn
2012-07-03 14:22 ` [PATCH v2 04/12] spi-orion: add device tree binding Andrew Lunn
2012-07-03 14:22 ` [PATCH v2 05/12] ARM: kirkwood: use devicetree for orion-spi Andrew Lunn
2012-07-03 14:22 ` [PATCH v2 06/12] ARM: kirkwood: use devicetree for SPI on dreamplug Andrew Lunn
2012-07-03 14:22 ` [PATCH v2 07/12] I2C: MV64XXX: Add Device Tree support Andrew Lunn
2012-07-03 15:59   ` Florian Fainelli
2012-07-03 16:58     ` Andrew Lunn
2012-07-04 19:49       ` Florian Fainelli
2012-07-05  6:52         ` Andrew Lunn
2012-07-03 14:22 ` [PATCH v2 08/12] Kirkwood: Add basic device tree support for QNAP TS219 Andrew Lunn
2012-07-03 15:47   ` Florian Fainelli
2012-07-03 17:09     ` Andrew Lunn
2012-07-03 14:22 ` [PATCH v2 09/12] ARM: Kirkwood: DTify the watchdog timer Andrew Lunn
2012-07-03 14:22 ` [PATCH v2 10/12] ATA: sata_mv: Add device tree support Andrew Lunn
2012-07-03 14:22 ` [PATCH v2 11/12] ARM: Kirkwood: Use DT to configure SATA device Andrew Lunn
2012-07-03 14:52   ` Josh Coombs
2012-07-03 15:32     ` Andrew Lunn
2012-07-03 14:22 ` [PATCH v2 12/12] Crypto: CESA: Add support for DT based instantiation Andrew Lunn
2012-07-03 15:50   ` Florian Fainelli
2012-07-03 17:03     ` Andrew Lunn

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